GENOTYPE VS. PHENOTYPE
Continue filling in your Vocabulary
Chart using the definitions and
examples provided here.
LEARNING TARGET
I
recognize that genes carry
information which determines
traits.
GENE & TRAIT

Gene: One section of DNA with instructions for
a trait

Trait: A characteristic or feature determined by
genes.

You have genes for each of the following traits:





Hair color
Eye color
Hitchhiker’s thumb
Tongue rolling
Height
ALLELE

The different forms of a gene.

Examples:
 Hitchhiker’s
thumb OR Straight thumb
 Can roll tongue OR Can’t roll tongue
 Blonde hair OR Black hair OR Brown hair OR Red hair

(Note: One allele comes from each parent.)
DOMINANT

Alleles that cover up all other alleles.
 Hides,
covers, masks, or over-powers
 Always shows up when present (it dominates!)

Shown with UPPERCASE letters.

Examples:
H
B
A
RECESSIVE

Alleles that get covered up by dominant alleles.

Shown with lowercase letters.

Examples:
h
b
a
HOMOZYGOUS
When both alleles are the SAME
 Homo = same


Examples:
 HH
= homozygous DOMINANT
 hh = homozygous RECESSIVE
HETEROZYGOUS
When both alleles are DIFFERENT
 Hetero = different


Examples:
 Hh
 Qq
 Rr
GENOTYPE
The genes that an organism has
(Genotype = Genes)
 Represented by letters


Examples:
 Hh
 BB
 tt
 Qq
PHENOTYPE

The traits or characteristics of an organism
 What
it looks like

(Phenotype = Features)

Examples:
 Hair
color
 Eye color
 Hitchhiker’s thumb
 Tongue rolling
 Height
EXAMPLES/PRACTICE
EYE COLOR
BROWN IS DOMINANT TO BLUE
(Use the letter “b”)
B = brown allele (dominant)
.
b = blue allele (recessive)
BRAD PITT
Brown is dominant to blue.
Brad has blue eyes.
What is his PHENOTYPE?
What is his GENOTYPE?
BRAD PITT
Brown is dominant to blue.
PHENOTYPE: blue eyes
GENOTYPE: bb
JUSTIN BIEBER
Justin has brown eyes.
What is his PHENOTYPE?
What is his GENOTYPE?
Brown is dominant to blue.
JUSTIN BIEBER
PHENOTYPE: brown eyes
GENOTYPE: BB or Bb
Brown is dominant to blue.
HAIRLINE
(use the letter “h”)
WIDOW’S PEAK IS DOMINANT TO
STRAIGHT HAIRLINE
Widow’s peak is dominant to normal hairline.
JOHN TRAVOLTA
John has a widow’s peak.
What is his PHENOTYPE?
What is his GENOTYPE?
Widow’s peak is dominant to normal hairline.
JOHN TRAVOLTA
PHENOTYPE: widow’s peak
GENOTYPE: HH or Hh
LEBRON JAMES
Widow’s peak is dominant to normal hairline.
LeBron has a straight hairline.
What is his PHENOTYPE?
What is his GENOTYPE?
LEBRON JAMES
Widow’s peak is dominant to normal hairline.
PHENOTYPE: straight hairline
GENOTYPE: hh
SKIN
(use the letter “f”)
FRECKLES ARE DOMINANT TO NO
FRECKLES
JENNIFER LOPEZ
Freckles are dominant to no freckles.
JLo has no freckles.
What is her PHENOTYPE?
What is her GENOTYPE?
JENNIFER LOPEZ
Freckles are dominant to no freckles.
PHENOTYPE: no freckles
GENOTYPE: ff
LINDSAY LOHAN
Lindsay has freckles.
What is her PHENOTYPE?
What is her GENOTYPE?
Freckles are dominant to no freckles.
LINDSAY LOHAN
PHENOTYPE: freckles
GENOTYPE: FF or Ff
Freckles are dominant to no freckles.
DIGITS (FINGERS AND TOES)
(use the letter “d”)
POLYDACTYLY IS DOMINANT TO 5 DIGITS
“NORMAL” 5 DIGITS
Polydactyly is dominant to 5 digits.
These people have 5 digits.
What is the PHENOTYPE?
What is the GENOTYPE?
“NORMAL” 5 DIGITS
Polydactyly is dominant to 5 digits.
PHENOTYPE: 5 digits
GENOTYPE: dd
Polydactyly is dominant to 5 digits
POLYDACTYLY (EXTRA DIGITS)
These people have Polydactyly.
What is the PHENOTYPE?
What is the GENOTYPE?
Polydactyly is dominant to 5 digits
POLYDACTYLY (EXTRA DIGITS)
PHENOTYPE: Polydactyly
GENOTYPE: Dd or DD
MORE PRACTICE
ALBINISM (RECESSIVE)
RIHANNA
Brown is dominant to blue.
Rihanna has brown eyes.
What is her PHENOTYPE?
What is her GENOTYPE?
RIHANNA
Brown is dominant to blue.
PHENOTYPE: brown eyes
GENOTYPE: BB or Bb
LADY GAGA
Freckles are dominant to no freckles.
Lady Gaga has
no freckles.
What is her PHENOTYPE?
What is her GENOTYPE?
LADY GAGA
Freckles are dominant to no freckles.
Lady Gaga has
no freckles.
PHENOTYPE: no freckles
GENOTYPE: ff